Cytological behaviour of the somatic hybrids Passiflora edulis f. flavicarpa + P. cincinnata     

L. V. Barbosa    M. Mondin    C. A. Oliveira    A. P. Souza    M. L. C. Vieira 《Plant Breeding》2007,126(3):323-328

Meiosis and pollen viability of interspecific somatic hybrids, i.e. Passiflora edulis f. flavicarpa , the yellow passion fruit +  P. cincinnata , a wild species, were examined and compared with their corresponding diploid fusion parents. Firstly, the cybrid nature of these hybrids was confirmed by leaf-stomatal measurements and RFLP analyses using four mitochondrial genes as probes. The meiotic behaviour revealed relatively high stability, with most of the hybrid cells showing 18 bivalents. Some instability, such as a quadrivalent configuration was also recorded which has been interpreted as an interchange that occurred in the progenitors more than as a result of in vitro culture or chromosome reorganization in the new genome. Even in low frequencies, the occurrence of univalents resulted in mis-division, laggard and micronucleus formation. High values of pollen viability (>70%) were found in the diploid parents as well as in the hybrid plants. The results are discussed in relation to the possibilities of applying somatic hybridization for improving passion fruit varieties.  相似文献   

Study of the genetic variability and similarity among and within Arachis villosulicarpa, A. pietrarellii and A. hypogaea through isoenzyme analysis     

Leticia Galgaro  Jose´ Francisco Montenegro Valls  Catalina Romero Lopes 《Genetic Resources and Crop Evolution》1997,44(1):9-15

Arachis villosulicarpa is a perennial species cultivated for its soft and tasty seeds by indigenous inhabitants of the Mato Grosso State, Brazil. Besides A. hypogaea, this species is considered as the only species of Arachis which represents a valuable food source for human consumption. Due to the lack of knowledge concerning the genetic diversity of A. villosulicarpa, this study was conducted to evaluate the genetic variability of the accessions from the Germplasm Collection of CENARGEN/EMBRAPA (Brasília, DF, Brazil) and Instituto Agrono^mico (IAC, Campinas, SP, Brazil). In addition, the genetic similarity between A. villosulicarpa, the related wild species A. pietrarellii, and the cultivated peanut A. hypogaea cv. Tatu was evaluated. From the entire sample analyzed of A. villosulicarpa, the accession from Instituto Agrono^mico showed the highest indices of diversity for both enzymatic systems analyzed, pointing this accession as a promising source of genetic variabil ity that must be preserved in the Germplasm Bank. A high level of genetic similarity was observed between A. pietrarellii and A. villosulicarpa, supporting previous suggestions that A. pietrarellii could be the ancestral progenitor species of A. villosulicarpa or that both species originated from a common ancestor.  相似文献   

Effective population size in a bottlenecked fur seal population     

Larissa Rosa de Oliveira  Milena Arias-Schreiber  João S. Morgante 《Biological conservation》2006,131(4):505-509

The census population size (N) is usually the only information available for most threatened species. For evolutionary matters, the effective population size (N_e), not the census number, is a prime concern. Factors such as variation in the sex ratio of breeding individuals, variation of population size in different generations and mating system are important. The South American fur seal, Arctocephalus australis, has been exploited in Peru by humans since ca. 2000 BC and now the original population declined 72%, as a result of low food availability during the severe El Niño in 1997-1998. In this sense A. australis is now classified as in danger of extinction in Peru. We present the first estimate of N_e of the Peruvian population of A. australis that takes into account the effects of mating system and variation in population size caused by the 1997-1998 El Niño. The resulting N_e was 2153 specimens. We believe that the estimated N_e for the Peruvian population is a critical value, because it is significantly lower than the mean minimum viable population for vertebrates (7000 breeding age adults). This estimated N_e is of critical importance because combined with the current El Niño events are reasons of great concern for the survival of the species and should be taken into account in future management plans to ensure the conservation and protection of the species in the Peruvian coast.  相似文献   

Incidence and viability of Acremonium endophytes in tall fescue accessions from North Spain     

J.A. Oliveira  V. Castro 《Genetic Resources and Crop Evolution》1997,44(6):519-522

The tall fescue (Festuca arundinacea Schreb.) seed collection of the Centro de Investigaciones Agrarias de Mabegondo was surveyed to determine Acremonium infection rates. One hundred seeds from each of 19 accessions were microscopically examined for endophyte. Seventeen accessions (90%) contained endophyte with a range of 7 to 100%. Leaf sheaths of seedlings from the infected accessions were examined to determine the percentage of infection with viable endophyte. Only seven (41%) of the seventeen infected accessions collected and stored in 1995 at 4°C and 45–50% relative humidity contained viable endophyte with a range of 70 to 100%. While existing germplasm collections of Festuca arundinacea can provide only a small basis of Acremonium germplasm for study, newly collected Festuca arundinacea accessions will offer a greater diversity of Acremonium genotypes.  相似文献   

Impact of urban development on streamflow regime of a Portuguese peri-urban Mediterranean catchment     

Carla Sofia Santos Ferreira  Rory Peter Dominic Walsh  João Pedro Carvalho Nunes  Tammo S. Steenhuis  Manuel Nunes  João Luís Mendes Pedroso de Lima  Celeste Oliveira Alves Coelho  António José Dinis Ferreira 《Journal of Soils and Sediments》2016,16(11):2580-2593

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Discriminate analysis of roasted coffee varieties for trigonelline, nicotinic acid, and caffeine content     

Casal S  Oliveira MB  Alves MR  Ferreira MA 《Journal of agricultural and food chemistry》2000,48(8):3420-3424

Arabica and robusta roasted coffees from several geographical origins, in a total of 29 samples, were characterized for their contents in caffeine, trigonelline, and nicotinic acid by a recently developed HPLC/diode-array detector method. All samples were subjected to the same roasting procedure in order to eliminate the variations due to this process. Characterization was achieved by applying multivariate and nonparametric analysis to the chromatographic results. The two coffee varieties were clearly separated by their trigonelline and caffeine contents. Nicotinic acid could not be used as a variety discriminate factor. There was no association with the geographical origin of the samples.  相似文献   

Indicator taxa of spider (Araneae) diversity and their efficiency in conservation     

Pedro Cardoso  Israel Silva  Nuno G. de Oliveira  Artur R. M. Serrano 《Biological conservation》2004,120(4):517-524

A considerable number of alternative approaches have been suggested during the last years to predict species richness of a given taxon, while retaining information on the identities of the observed individuals. Such information can be extremely useful for choosing conservation priority areas, either by using raw richness values or, preferentially, by considering the complementarity between potential sites. Among the most popular approaches is the use of indicator taxa. Both one single family and a group of several families are here tested in their ability to predict the number of spider (Araneae) species independently of sampling effort, geographical location and type of habitat. We use data from three Portuguese protected areas as a test case. A two-family indicator group – Gnaphosidae and Theridiidae – is found to be a good surrogate of species richness, even if caution is needed regarding the comparison of sites with considerably different sampling effort or vegetation cover. No single family can be seen as a good surrogate of the totality of spiders. In addition, only a group of the two mentioned families is found to be efficient and reliable either when used to rank sites according to taxa richness or for determining near-minimum sets of sites for conservation. We therefore recommend surrogacy with this indicator group as a promising approach for the prediction of spider species richness or evaluation and ranking of areas according to their conservation importance. The reached conclusions should uphold for Portugal and the entire Mediterranean region.  相似文献   

Evaluation of some carotenoids in grapes by reversed- and normal-phase liquid chromatography: a qualitative analysis     

Mendes-Pinto MM  Ferreira AC  Oliveira MB  Guedes de Pinho P 《Journal of agricultural and food chemistry》2004,52(10):3182-3188

Carotenoids in grapes of three Port winemaking cultivars were investigated. Extracts were obtained with n-hexane/diethyl ether mixtures (0/100; 20/80; 50/50; 100/0) and analyzed by normal and reversed phase HPLC-DAD. Selection and identification of peaks were based on spectroscopic characteristics - lambda(max), (%III/II) and k' values, leading to 28 probable carotenoids. Using pure standards, it was possible to identify seven compounds previously described (neochrome, neoxanthin, violaxanthin, flavoxanthin, zeaxanthin, lutein, and beta-carotene), one more type of neochrome reported here, for the first time, and in addition, two geometrical isomers of lutein and beta-carotene were tentatively described. The remaining 17 need to be further identified. High polarity solvent mixtures lead to qualitatively richer chromatograms. Reversed-phase separations allowed the detection of flavoxanthin and the possible geometrical isomer(s) of beta-carotene. Under normal phase, zeaxanthin was detected, and neochromes were better separated from neoxanthin. Extraction with 50/50 n-hexane/diethyl ether mixtures and reversed-phase conditions was the best combination for analysis of the carotenoids, known as precursors of compounds with high aroma impact in wines.  相似文献   

Evaluation of residual levels of benomyl, methyl parathion, diuron, and vamidothion in pineapple pulp and bagasse (Smooth cayenne)     

Cabrera HA  Menezes HC  Oliveira JV  Batista RF 《Journal of agricultural and food chemistry》2000,48(11):5750-5753

The objective of this research was to study the residual levels of benomyl, methyl parathion, diuron, and vamidothion in pineapple bagasse and pulp. Benomyl (benlate), methyl parathion (Folidol 600), diuron (Krovar), and Vamidothion (Kilval 300) were applied pre-harvest to pineapples (smooth cayenne). After harvesting, the fruits were washed (100 ppm sodium hypochlorite) and the pulp was separated from the sub-products (peel, core, tops, and tails). The pulp was not submitted to any heat treatment. The sub-products and the juice expressed from them, were submitted to a blanching process (95 degrees C for 1 min). After separating the juice, the bagasse and pulp were analyzed for residues of diuron and benomyl by high performance liquid chromatography, and for residues of vamidothion and methyl parathion by gas chromatography using a TSD detector. No residues of benomyl, diuron, vamidothion, or methyl parathion were detected in the pulp within the quantification limits of the methods (0.1 mg/kg, 0.1 mg/kg, 0.005 mg/kg, and 0.005 mg/kg, respectively). Only methyl parathion (0.052 mg/kg) and vamidothion (0.021 mg/kg) were detected in the bagasse. The presence of these residues in the bagasse was probably due to the action of the wax found in the peel, which prevented the methyl parathion and vamidothion from dissolving in the juice. According to these results, the pulp was fit for human consumption, as far as pesticide residues were concerned, and the bagasse was fit for animal feed and similar applications, because the residual levels found were below the limits established for these compounds.  相似文献   

Quantitation of nine organic acids in wild mushrooms   总被引：3，自引：0，他引：3  

Valentão P  Lopes G  Valente M  Barbosa P  Andrade PB  Silva BM  Baptista P  Seabra RM 《Journal of agricultural and food chemistry》2005,53(9):3626-3630

The organic acids composition of six wild edible mushroom species (Amanita caesarea, Boletus edulis, Gyroporus castaneus, Lactarius deliciosus, Suillus collinitus, and Xerocomus chrysenteron) was determined by an HPLC-UV detector method. The results showed that all of the samples presented a profile composed of at least five organic acids: citric, ketoglutaric, malic, succinic, and fumaric acids. Several samples also contained oxalic, ascorbic, quinic, and shikimic acids. In a general way, the quantitation of the identified compounds indicated that malic acid, followed by the pair citric plus ketoglutaric acids, were the main compounds in the analyzed species, with the exception of A. caesarea, in which malic and ascorbic acids were the most abundant compounds. The relative amounts and the presence/absence of each identified compound may be useful for the differentiation of the species.  相似文献